Which of the following metal-acid combination will shift metal from active to passive state with an increase in oxidizer concentration?

Which of the following metal-acid combination will shift metal from ac

1.	Which of the following metal-acid combination will shift metal from active to passive state with an increase in oxidizer concentration?
A.	Monel in HCl+O<sub>2</sub>
B.	18Cr-8Ni in H<sub>2</sub>SO<sub>4</sub>+Fe<sup>+3</sup>
C.	Fe in H<sub>2</sub>O+O<sub>2</sub>
D.	18Cr-8Ni in HNO<sub>3</sub> + Cr<sub>2</sub>O<sub>3</sub>
Answer» C. Fe in H<sub>2</sub>O+O<sub>2</sub>